Push-pull door latch construction



Aug. 2, 1966 E. M. HAWES PUSH-PULL DOOR LATCH CONSTRUCTION Filed April 14, 1964 INVENTOR. EDWARD M. HAWES IWHHIII I IIUIIIH" ATTORNEYS United States Patent 3,264,025 PUSH-PULL DOOR LATCH CONSTRUCTION Edward M. Hawes, 32418 Birkshire Road, St. Clair Shores, Mich. Filed Apr. 14, 1964, Ser. No. 359,612 12 Claims. (Cl. 292166) This invention relates to latches and, in particular, to door latches.

One object of this invention is to provide a push-pull door latch which is operable to retract the latch bolt by pushing or pulling upon a handle in one continuous motion upon the outer or inner side respectively of the door, thereby enabling the door to be opened from the outside by pushing against it with the body when the use of the hands is restricted, as by holding packages.

Another object is to provide a push-pull door latch of the foregoing charatcer wherein the latch is retracted by the action of a cam nut rotated arcuately by a reciprocable shaft with a high pitch thread or fast screw thread which is prevented from rotation while being pushed or pulled, thereby converting reciprocating motion of the shaft in the direction of handle pull into reciprocation of the latch bolt along an axis perpendicular to that of the shaft.

Another object is to provide a push-pull door latch of the foregoing character wherein the operating mechanism for retracting and projecting the latch is contained within a tubular casing which is thereby simply and quickly in-, stalled in the door by mere drilling operations.

Another object is to provide a push-pull door latch as set forth in the object immediately preceding, wherein the installation in the door of the high-pitch-thread reciprocable shaft is also accomplished simply and rapidly by a drilling operation at right angles to the bore containing the tubular latch bolt casing and its operating mechanism.

Another object is to provide a push-pull door latch of the foregoing character which may be installed in anytype of door and in which all of the operating mechanism except the handles may be standardized yet permit wide variation of design of handles in order to adapt it to different architectural requirements.

Other objects and advantages of the invention will become apparent during the course of the following description of the accompanying drawing, wherein:

FIGURE 1 is an end elevation of a portion of a door equipped with the push-pull latch according to one form of the invention, with the positions of the moving parts in solid lines in the latched position of the door and in dotted lines in the unlatched position thereof;

FIGURE 2 is a right-hand side elevation of the pushpull latch shown in FIGURE I, viewed from the inner side of the door;

FIGURE 3 is a vertical longitudinal section through the latch boh mechanism and casing, taken along the line 33 in FIGURE 1, with the latch bolt projected into doorlatching position; a I

FIGURE 4 is a vertical longitudinal section similar to FIGURE 3 but showing the positions of the moving parts with the latch bolt in its retracted position corresponding to the dotted line positions of the moving parts in FIG- URE 1;

FIGURE 5 is a horizontal section taken along the line 5-5 in FIGURE 1, showing'thepositions of the moving parts in the projected position of the latch bolt;

FIGURE 6 is a cross-section along the line 6-6 in FIGURE 5, showing details of the cam nut; and

FIGURE 7 is a cross-section along the line 7-7 in FIGURE 5, showing details of the abutment of the latch bolt projecting spring.

Referring to the drawings in detail, FIGURE 1 shows Patented August 2, 1966 a push-pull door latch, generally designated 10, as installed in a door 12 preferably a door of the swinging type, having hinges on the opposite edge (not shown) of the door from the edge face 14 through which the latch bolt of the latch 10 projects, as more fully described below. The door 12 has an outside face 16 and an inside face 18 which, if the door 12 is an outside door, is within the building to which access is given by the door 12.

Mounted on the outside and inside faces 16 and 18 are outside and inside latch handle units 20 and 22 respectively, each having a mounting plate 24 carrying laterallyspaced projecting ears 26 drilled to receive a pivot pin 28. The pivot pin 28 pivotally supports the bored hub 30 of a push-pull latch handle, generally designated 32. The latch handle 32 may be made in any suitable design according to the architectural requirements or the desires of the owner, the open-centered trapezoidal shape with diverging handle arms 34 (FIGURE 2) connecting the handle bar 36 to the hub 30 being shown for purposes of illustration without limitation. It will be obvious, for example, that a ring might likewise be used and mounted upon the pivot pin 28 by means of a chordal portion.

Secured as by welding to the hub 30 and projecting downwardly therefrom with its central plane at an acute angle to the central plane of the latch handle 32 is a lever arm or operating arm 38, the tapered lower end portion 40 of which terminates in laterally-spaced cylindrical bosses 42 separated from one another by a narrow slot 44 between their inner ends 46 (FIGURES 2 and 5). Operatively engaged by the bosses 42 is a reciprocable operating shaft, generally designated 48, with opposite spaced outer end flanges 50 and 52 separated from one another by a narrow fiat-sided neck portion 54 lying in the slot 44 between the opposite inner ends 46 of the bosses 42. In this manner, the shaft 48 is prevented from rotating while being reciprocated by the push-pull action of the outer or inner latch handle units 20 and 22 against the flanges 50 and 52 as described below.

The shaft 48 between the inner flanges 52 is provided with a high-pitched-thread or fast screw thread intermediate portion 56 and is urged outwardly by a helical compression spring 58 extending between the inner flange 52 on the outside of the door and a cup-shaped abutment 60 countersunk into the outer face 16 of the door 12 through a hole 62 in the mounting plate 24 thereof (FIGURE 5). Intermediate its opposite ends, the high or fast pitch or thread intermediate portion 56 of the shaft 48 passes through the mating internally-ribbed mating thread bore 64 in the hub 66 of a cam nut 68 having a semi-circular arcuate rib 70 thereon (FIGURES 3 and 4) terminating at its opposite ends in abutment shoulders 72. The abutment shoulders 72 in turn are Operatively engageable with abutment lugs or shouldered cam follower projections 74 on the spaced parallel upper and lower edges 76 of the hollow semi-cylindrical body 78 of a reciprocable latch bolt, generally designated 80, having a bolt nose 82 at its forward end, a circular bearing disc 84 at its rearward end and an elongated slot 86 therebetween (FIGURES 3, 4 and 5). From FIGURE 5 it will be seen that the abutment lugs 74 project transversely from the edges 76 into the path of swing of the abutment shoulders 72 of the rotatable arcuate rib 70 of the cam nut 68. From a comparison of FIGURES 3 and 4, it will be evident that the thread of the shaft portion 56 is required to extend only approximately halfway around the shaft 48 or less than degrees in order to actuate Y the cam nut 68 sufiiciently.

The latch bolt nose 82 is of circular cross-section and of the same diameter asthe rearward bearing disc 84. These have reciprocatory bearing engagement with the cylindrical bore 88 of a cup-shaped cylindrical latch bolt casing or bolt support 90 composed of opposite semicylindrical halves 92 and 94 respectively (FIGURE The casing. 90 is seated in an elongated cup-shaped or blind bore 96 extending horizontally into the door 12 from the front edge face 14 thereof. The outer half 94 is provided with an integral rectangular face plate 98 which is set into a correspondingly-shaped rectangular recess 100 in the front edge face 14 of the door 12 and secured thereto by screws or other suitable fasteners 102 (FIGURES 1 and 5). Seated in aligned holes 104 and 106 (FIGURES 5 and 7) in the opposite casing halves 92 and 94 and extending intermediately through the slot 86 are the opposite ends of a spring abutment pin 108 which also serves as a guide pin preventing rotation of the latch bolt 80 in the casing bore 88. Disposed within the casing bore 88 between the pin 108 and the rear surface 110 of the bolt nose 82 is a precompressed helical compression spring 112 which constantly urges the bolt nose 82 outwardly into the latch keeper (not shown) in the door frame or door post (also not shown) in which the door 12 is mounted. The inner mounting plate 20, the casing halves 92 and 94, and the cup-shaped abutment 60 are also provided with aligned holes 114, 116, 118 and 120 in which the threaded shaft 48 is rotatably mounted.

For simplification of disclosure, the operating shaft 48 is shown as made in a single piece, whereas as actually constructed, the shaft is made in two pieces for purposes of convenience of assembly, with the rearward or righthand end portion including the inside flanges 50 and 52 and their connecting portion 54 made in a separate piece and secured to the remainder of the shaft 48 by fasteners (not shown). In order to provide clearance for the motion of the arcuate cam rib 70 and lugs 74, the casing 90 is provided with top and bottom slot-s 122 and 124 respectively (FIGURES 3 and 4).

In the operation of the invention, let it be assumed that the door 12 is in its closed and latched position with the latch bolt nose 82 projected as shown in FIGURES 3 and 5 into the latch keeper (not shown) with the moving parts in their solid line positions shown in FIGURE 1. Let it also be assumed that a person is on the outside or left-hand side of the door 12 in FIGURE 1, facing its outside surface 16, and desires to unlatoh the door and enter by swinging the door inward or to the right in FIGURE 1. To do so, the operator pushes against the handle 36 of the outside handle unit 20, either by his hand, if available, or by pressing against it with his body. This action swings the latch handle 32 downward into the dotted line position in the lower left-hand corner of FIGURE 1, thereby swinging the lever arm 38 to the right, causing its lower end bosses 42 to press against the flange 52 and move the fast-thread or high-pitch operating shaft 48 inwardly to the right, compressing the compression spring 58, at the same time preventing the shaft 48 from rotating by the action of the inner ends 46 of the bosses 42 upon the narrowed neck portion 54 of the shaft 48.

The inward motion of the non-rotating shaft 48 causes its fast-thread intermediate portion 56 to rotate the hub 66 of the cam nut 68 as it passes through the internallyribbed bore 64 thereof (FIGURE 3), swinging its arcuate cam rib 70 through an angle of approximately 45 degrees into theposition shown in FIGURE 4, causing one endshoulder 72 thereof to push one of the latch bolt lugs 74 rearwardly and thereby pulling the nose 82 of the bolt 80 rrearwardly to its connection effected by the semi cylindrical ,bolt body portion 78. -This action simultaneously compresses the spring 112 against its abutment 108,,which at the same time engages the edges of the slot 86 to prevent rotation, of the bolt 80 within the casing90. I I

With the door thus unlatched, the operator continues pushing upon the outside handle unit 20 to swing the door inward and gain access to the interior of the room or building equipped with the door 12. When the operator releases the handle unit 20, however, the previouslycompressed spring 58 expands, pushing the shaft 48 and handle unit 20 outwardly to the left to their solid line position-s, retracting the fast-thread shaft 48 from the position shown in FIGURE 4 and consequently permitting the previously-compressed spring 112 to project the nose 82 of the latch bolt into the latch keeper from the retracted position of FIGURE 4 to the latching position of FIGURE 3.

If, on the other hand, a person is on the inner side 18 of the door 12 and wishes to unlatch the door and pass outward, he grasps the handle bar 36 of the inside handle unit 22 and pulls it toward him, thereby causing the operating arm or lever arm 38 to swing to the right into the dotted line position of FIGURE 1, again pulling the fastthread shaft 48 to the right into the dotted line position and repeating the unlatching operation described above in gaining access from the outside of the door. In short, this action rotates the cam nut 68 from the latching position of FIGURE 3 into the unlatching position of FIG- URE 4, retracting the nose 82 of the latch bolt 80 and again unlatching the door 12. By continuing to pull upon the handle bar 36 of the inside handle unit 22, the operator pull-s the door 12 inwardly to the right toward himself, thereby opening the door, and passes outward through the door opening. What I claim is:

1. A push-pull door latch construction, comprising a latch bolt support,

a latch bolt slidably mounted in said support and having a cam follower portion thereon,

a cam nut rotatably mounted adjacent said latch bolt support and having a cam portion operatively engageable with said cam follower portion and effecting sliding motion of said latch bolt in response to rotation of said cam nut,

said cam nut having an internally-threaded bore therethrough,

a slidably-mounted threaded operating shaft threadedly engaging said bore in approximately perpendicular relationship to said latch bolt,

the portion of the thread of said shaft engageable with said cam nut bore being a fast-pitch thread extending less than halfway therearound, means engageable with said shaft for preventing rotation thereof, and a handle structure operatively connected to said shaft for effecting sliding motion thereof transversely to said bolt.

2. A push-pull door latch construction, according to claim 1, wherein a first resilient element is interposed between said latch bolt and said latch bolt support and urges said latch bolt in a sliding direction opposite to that eflected by said cam nut.

3. A push-pull door latch construction, according to claim 2, wherein a second resilient element is disposed adjacent said shaft and urges said shaft slidably in one direction.

4. A push-pull door latch construction, according to claim 3, wherein said second resilient element encircles said shaft.

5. A push-pull door latch construction, according to claim 3, wherein said handle structure includes a handle plilvtgtally mounted for swinging motion relatively to said 8 a t.

6. A push-pull door latch construction, according to claim 5, wherein said latch construction also includes a mounting member attachable to the door, said handle being pivotally mounted on said mounting member.

7. A push-pull door latch construction, according to claim 3, wherein said handle structure includes a pair ofhandles operatively connected to the opposite ends of said shaft.

8. A push-pull door latch construction, according to claim 7, wherein said latch construction includes a pair of mounting members attachable to the door on opposite sides thereof and wherein one of said handles is pivotally mounted on one of said mounting members and the other handle member is pivotally mounted on the other handle member.

9. A push-pull door latch construction, according to claim 5, wherein said shaft rotation-preventing means includes a flattened portion of said shaft and a notched portion of said handle engaging said flattened Shaft portion.

10. A push-pull door latch construction, according to claim 1, wherein said cam follower portion includes a projection on said latch bolt and wherein said cam portion includes a shoulder on said cam nut operatively engaging said projection. I

11. A push-pull door latch construction, according to claim 1, wherein said cam follower portion includes a pair of transversely-spaced projections on said latch bolt,

References Cited by the Examiner UNITED STATES PATENTS 886,635 5/1908 Pool et a1 292-172 1,102,313 7/1914 Yates et a1 292172 1,177,445 3/1916 Rader 292172 1,211,437 1/1917 Bruber 292-172 2,431,105 ll/ 1947 Brinson 292----172 PATRICK A. CLIFFORD, Primary Examiner.

J. R. MOSES, Assistant Examiner. 

1. A PUSH-PULL DOOR LATCH CONSTRUCTION, COMPRISING A LATCH BOLT SUPPORT, A LATCH BOLT SLIDABLY MOUNTED IN SAID SUPPORT AND HAVING A CAM FOLLOWER PORTION THEREON, A CAM NUT ROTATABLY MOUNTED ADJACENT SAID LATCH BOLT SUPPORT AND HAVING A CAM PORTION OPERATIVELY ENGAGEABLE WITH SAID CAM FOLLOWER PORTION AND EFFECTING SLIDING MOTION OF SAID LATCH BOLT IN RESPONSE TO ROTATION OF SAID CAM NUT, SAID CAM NUT HAVING AN INTERNALLY-THREADED BORE THERETHROUGH, A SLIDABLY-MOUNTED THREADED OPERATING SHAFT THREADEDLY ENGAGING SAID BORE IN APPROXIMATELY PERPENDICULAR RELATIONSHIP TO SAID LATCH BOLT, THE PORTION OF THE THREAD OF SAID SHAFT ENGAGEABLE WITH SAID CAM NUT BORE BEING A FAST-PITCH THREAD EXTENDING LESS THAN HALFWAY THEREAROUND, MEANS ENGAGEABLE WITH SAID SHAFT FOR PREVENTING ROTATION THEREOF, AND A HANDLE STRUCTURE OPERATIVELY CONNECTED TO SAID SHAFT FOR EFFECTING SLIDING MOTION THEREOF TRANSVERSELY TO SAID BOLT. 